Fused plug connector



4, 1949. H C, ROHRMAN 2$452 l FUSED PLUG CONNECTOR Filed July 2o, 194eXNVENTOR (vDRNEY o@ Patented Jan. 4, 1949 FUSED PLUG CONNECTOR Henry C.-Rohrman, Philadelphia, Pa., assignor of one-half to Frank P. Murphy,Philadelphia, Pa.

Application July 20, 1946. Serial No. 685,232

2 Claims. l

My invention relates to electrical attachment plugs.

A purpose oi my invention is to reduce the likelihood of burning out amain fuse of the house wiring, and simplify the location of electricaltrouble and the replacement of fuses.

A further purpose is to simplify and cheapen the mounting of electricalfuses.

A further -purpose is to construct an electrical plug connector having ahollow insulating body, a pair of plug contacts mounted in insulatedcondition on the body and extending from one face of the body inparallel spaced relation, a iirst terminal within the body directlyelectrically connected to one of the plug contacts, a second terminalwithin the body insulated from both contacts and from the firstterminal, a fuse within the body and means for connecting the fusebetween the other plug contact and the second terminal.

A further purpose is to position the second terminal behind and inprolongation of the other plug contact, mount a fuse socket near theinner end of the other plug contact, mount a cooperating fuse socket onthe second terminal and position a fuse in the fuse sockets extending in.general prolongation of the other plug contact.

A further purpose is to position an extension of insulating materialrearward of the plug front and provided with a side recess, to mount afuse socket on the rearward end of one plug contact adjacent the forwardend of the recess,and to mount a terminal and cooperating fuse socket onthe extension near the rearward end of the recess, so that, with therear of the socket removed, access to the fuse can be obtained at theside of the extension in the recess.

Further purposes appear in the specification and in the claims.

In the drawing I have chosen to illustrate one only of the numerousembodiments in which my invention may appear, the form shown beingchosen from the standpoints of convenience in illustration, satisfactoryoperation and clear demonstration of the principles involved.

Figure 1 is a perspective View of the plug connector of my invention. A

Figure 2 is a section of Figure 1 on the line Figure 3 is a detachedperspective of the other plug contact, the second terminal and the fuse.

Figure 4 is a section on the line 4-4 of Figure 2.

Figure 5 is a broken detached perspective of the extension, recess andterminal mounted thereon.

Like numerals refer to like parts throughout.

Describing in illustration but not in limitation and referring to thedrawing:

Experience has indicated that the most frequent cause of electricaltrouble resulting in blowing fuses in household lighting and power isthe auxiliary equipment, such as extension cords, iloor lamps, tablelamps, vacuum cleaners, electric irons, washing machines, etc. The houseWiring itself is a less frequent cause of trouble.

If a fuse blows in the household fuse box the only easy way thehouseholder can locate the source of trouble is to disconnect the plugsto auxiliary equipment in the location involved, rev place the fuse andthen connect various auxiliaries into the line and observe whether thefuse again blows. If for example a given auxiliaryI has a short circuitin its cord, the initial trouble often does not disconnect the circuitlocally connecting that auxiliary to the house current.

By my invention I am able to connect a fuse into the local auxiliarycircuit, locating the fuse conveniently in the plug connector, so thatin case of trouble in theauxiliary the local fuse will blow, the housebox fuse normally will not blow, and the householder will immediatelyhave his attention directed to the auxiliary which is giving trouble.Replacement of the local fuse is made very easy in the structure of myinvention.

The plug connector 20 is intended to be of any well known domestic type,having an insulating body 2|, a pair of spaced generally parallel plugcontact pins 22 and 23 extending out from an insulator front surface 24which normally will face the floor or wall plug socket, and having ahollow interior 25 and a rear wire passage 26 for wires 21 of anextension cord or the like.

The body 2| may be of plastic such as phenolformaldehyde, or desirablyof rubber or synthetic rubber. The body 2| suitably comprises aninsulating front 28 which surrounds and supports at 29 the inner ends 30of the plug contacts 22 and 23, and a bell shaped insulating rear 3|.threaded together at 32. It will be noted that the body 2| is shoulderedforward of the point where the front 28 is threaded to the cover at I2.

Inside the hollow 25 of the body, the front is extended at 33 to supporttwo metallic terminals, 34 and 3l, preferably on opposite sides of theextension 33, to which the wires 21 are attached. The plug contact 22 ispreferably extended inward at 36 to receive the screw thread of the iterminal 34, the terminal simply in this case being a. screw,cooperating with the contact.

On-the opposite side, the metallic terminal 35 suitably comprises a lug3'| threaded at 38 for a terminal screw 39, reverse bent at 40 to extendon both sides of an insulation rib 4| on the extension 33, and carryingparallel to the lug a fuse socket 42 comprising spring fingers. A screw40' threaded through suitable holes in the terminal on both sides of therib 4|, and through a suitable hole in the rib 4|, secures the terminalin position.

The fuse socket 42 is positioned in a side recess 43 of the insulationextension 33 (best seen in Figures 4 and 5), and the insulation ispreferably provided with a flat wall 44 against which the side of theterminal 35 rests to prevent rocklng.

The recess 43 extends as shown to the inner end of the plug contact 23,which carries an arm 45 extending laterally parallel to inwardlyextending reverse bent portion of terminal 35 and mounts, on the side ofthe arm 45, a fuse socket 46 cooperating with the fuse socket 42, inline with it, and properly spaced from it to receive a fuse 4l havingterminals 48 and 49. The fuse lies in the recess 43.

It will be evident that the fuse when in place extends parallel to theplug contact 23 and substantially in prolongation thereof.

In operation the fuse will be inserted into the recess 43 and engagedby'the fuse sockets 42 and 46 while the rear 3| of the socket isremoved.

The wires will be threaded through the opening` 26 in the rear 3|, andattached to the terminals 34 and 35. Then the rear 3| will be screwedon, and the device will function as a standard plug connector.

In case of trouble, burning out the fuse, the rear 3| will be removed,the fuse replaced and the rear 3| reapplied` The device will then be lofinsulating material, a pair of plug contacts mounted in parallel spacedrelation on and extending through and beyond the front, a first terminalon the rear of one of the contacts, a rst fuse socket on the rear of theother contact, an extension of insulating material rearward from theplug front having a side recess which includes and extends behind saidfirst fuse socket and forms with the extension a rib -of insulatingmaterial at the back of the recess, a second terminal having a reversebend U portion extending on both sides of and secured to the rib and asecond fuse socket in line with and properly spaced from the first fusesocket to receive a fuse and mounted on the second terminal in tnerecess.

2. In an electrical plug connector, a plug front of insulating materialand circular contour having an outer shoulderrand male threads rearwardof the shoulder, a pair of plug contacts mounted in parallel spacedrelation on and extending straight through and straight beyond thefront, a i'lrst terminal directly on the rear of one of the plugcontacts, a first fuse socket on the rear of the other contact, anextension of insulating material extending straight rearwardly from theplug front having the first terminal at the sidewall of the extensionand having a side recess which includes and extends beyond the rst fusesocket and forms with the extension a rib of insulating materialtransverse to the extension and adjacent the back of the extension, asecond terminal having a U portion surrounding and mounted on the rib, asecond socket in line with and properly spaced from the rst socket toreceive a cartridge fuse and mounted on the second terminal in the"recess and a hollow cover surrounding and spaced from *he extension,having an opening for wires at the back and having female threads at theforward end cooperating with the male threads on the plug front andabutting against the shoulder.

HENRY C. ROHRMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,650,421 Brown Nov. 22, 19271,743,821 Kollath Jan.A 14, 1930 1,860,546 Manson May 31, 1932 1,926,936Casingena et al. Sept. l2, 1933

